Aluminum alloy brazing sheet and manufacturing method thereof

ABSTRACT

An aluminum alloy brazing sheet used for brazing of an aluminum material in an inert gas atmosphere or in vacuum is formed of a two-layer material in which a brazing material and a core material are stacked in this order. The core material is formed of an aluminum alloy and has a grain size of 20 to 300 μm, and the aluminum alloy contains Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of 1.00 mass % or less, with the balance being aluminum and inevitable impurities. The brazing material is formed of an aluminum alloy containing Si of 4.00 to 13.00 mass % with the balance being aluminum and inevitable impurities, and, in a drop-type fluidity test, a ratio α (α=Ka/Kb) of a fluid coefficient Ka is 0.50 or more.

TECHNICAL FIELD

The present invention relates to an aluminum alloy brazing sheet usedfor brazing an aluminum material in an inert gas atmosphere or in vacuumwithout using a flux.

BACKGROUND ART

Brazing joint is widely used as a method for joining products includinga number of minute joining portions, such as heat exchangers and machinecomponents formed of aluminum. To execute brazing joint for aluminummaterials (including aluminum alloy materials), it is indispensable tobreak an oxide film covering the surface of the material and bring themolten brazing material into contact with a base material or a similarlymolten brazing material. Methods for breaking the oxide film of thealuminum material are broadly divided into methods of using a flux andmethods of heating the material in vacuum, and both of them have beenput to practical use.

Brazing joint has a wide application range. Heat exchangers forautomobiles serve as the most representative product manufactured bybrazing joint. Most of heat exchangers for automobiles, such asradiators, heaters, capacitors, and evaporators, are formed of aluminum,and most of them are manufactured by brazing joint. A method of applyinga noncorrosive flux and heating the structure in nitrogen gas occupiesthe majority part of brazing joint at present.

However, in a flux brazing method, the cost for the flux and the costrequired for the step of applying the flux increase, and serve as thecause for increase in cost for manufacturing heat exchangers. There is amethod of manufacturing heat exchangers by vacuum brazing, but thevacuum brazing method requires high equipment cost and high maintenancecost for the heating furnace, and has the problem in productivity and/orbrazing stability. For this reason, there are increasing needs forexecuting brazing joint in a nitrogen gas furnace without using a flux.

To meet the needs, for example, Patent Literature 1 proposes a method ofdiffusing Mg added to the core material into the brazing material, as amethod enabling brazing joint in an inert gas atmosphere without using aflux by diffusing Mg into the brazing material during brazing heating.Patent Literature 1 discloses that the method prevents formation of anoxide film on the surface of the brazing material in manufacturing ofthe clad material and/or during brazing heating, and that Mg effectivelyacts on breakage of an oxide film on the surface of the brazingmaterial.

PRIOR ART LITERATURES Patent Literature

Patent Literature 1: Japanese Patent Application Laid-open No.2004-358519

SUMMARY OF INVENTION Problem to be Solved by Invention

However, the method of diffusing Mg added to the core material into thebrazing material requires securing the solidus temperature of the corematerial equal to or more than the brazing temperature, and the Mgquantity that can be added to the core material is limited. For thisreason, there are cases where no sufficient Mg quantity to break theoxide film in brazing can be added and good brazability cannot besecured.

In addition, even when the Mg quantity of the core material is limited,in the case where the grain size of the core material is small, there isthe problem that the shape of the heat exchanger cannot be maintainedbecause, for example, the core material is molten due to much diffusionof Si in the brazing material into the core material in brazing, or thecore material is molten due to much diffusion of Si in the brazingmaterial into the core material as a result of remaining subgrains in alow-processed portion at the time when pressing or the like is executedin brazing.

Accordingly, an object of the present invention is to provide analuminum alloy brazing sheet achieving excellent brazability. With thealuminum alloy brazing sheet, in the case of brazing an aluminummaterial in an inert gas atmosphere, such as a nitrogen gas atmosphere,or in vacuum without using a flux, Mg is promptly supplied into thebrazing material in brazing heating and sufficiently eluted into themolten brazing material after melting of the brazing material isstarted. This enables efficient breakage of the oxide film on thesurface of the brazing material, and suppresses diffusion of Si in thebrazing material into the core material in brazing heating.

Means for Solving the Problem

The problem described above is solved with the following presentinvention.

Specifically, the present invention (1) provides an aluminum alloybrazing sheet used for brazing of an aluminum material in an inert gasatmosphere or in vacuum and formed of a two-layer material in which abrazing material and a core material are stacked in this order,

the core material being formed of an aluminum alloy and having a grainsize of 20 to 300 μm, the aluminum alloy comprising Mn of 0.50 to 2.00mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of1.00 mass % or less, with the balance being aluminum and inevitableimpurities,

the brazing material being formed of an aluminum alloy comprising Si of4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities, and

in a drop-type fluidity test, a ratio α(α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied being 0.50 or more.

The present invention (2) provides the aluminum alloy brazing sheet of(1), wherein the brazing material further comprises one or two or moreof Bi of 1.00 mass % or less, Na of 0.050 mass % or less, Sr of 0.050mass % or less, Mg of 2.00 mass % or less. Zn of 8.00 mass % or less, Cuof 4.00 mass % or less, In of 0.100 mass % or less, Sn of 0.100 mass %or less, and Fe of 1.00 mass % or less.

The present invention (3) provides the aluminum alloy brazing sheet of(1) or (2), wherein the core material further comprises one or two ormore of Ti less than 0.10 mass %, Cu of 1.20 mass % or less, Zr of 0.30mass % or less, and Cr of 0.30 mass % or less.

The present invention (4) provides an aluminum alloy brazing sheet usedfor brazing of an aluminum material in an inert gas atmosphere or invacuum and formed of a three-layer material in which a brazing material,a core material, and a brazing material are stacked in this order,

the core material being formed of an aluminum alloy and having a grainsize of 20 to 300 μm, the aluminum alloy comprising Mn of 0.50 to 2.00mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of1.00 mass % or less, with the balance being aluminum and inevitableimpurities,

each of the brazing materials being formed of an aluminum alloycomprising Si of 400 to 13.00 mass % with the balance being aluminum andinevitable impurities, and

in a drop-type fluidity test, a ratio α (α=K_(a)/K_(b)K) of a fluidcoefficient Km after a 5% strain is applied to a fluid coefficient K_(b)before the strain is applied being 0.50 or more.

The present invention (5) provides the aluminum alloy brazing sheet of(4), wherein the brazing material further comprises one or two or moreof Bi of 1.00 mass % or less, Na of 0.050 mass % or less, Sr of 0.050mass % or less, Mg of 2.00 mass % or less, Zn of 8.00 mass % or less, Cuof 4.00 mass % or less, In of 0.100 mass % or less, Sn of 0.100 mass %or less, and Fe of 1.00 mass % or less.

The present invention (6) provides the aluminum alloy brazing sheet of(4) or (5), wherein the core material further comprises one or two ormore of Ti less than 0.10 mass %. Cu of 1.20 mass % or less, Zr of 0.30mass % or less, and Cr of 0.30 mass % or less.

The present invention (7) provides an aluminum alloy brazing sheet usedfor brazing of an aluminum material in an inert gas atmosphere or invacuum and formed of a three-layer material in which a brazing material,a core material, and a sacrificial anode material are stacked in thisorder,

the core material being formed of an aluminum alloy and having a grainsize of 20 to 300 μm, the aluminum alloy comprising Mn of 0.50 to 2.00mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of1.00 mass % or less, with the balance being aluminum and inevitableimpurities,

the brazing material being formed of an aluminum alloy comprising Si of4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities,

the sacrificial anode material being formed of aluminum or an aluminumalloy comprising Zn of 8.00 mass % or less with the balance beingaluminum and inevitable impurities, and

in a drop-type fluidity test, a ratio α(α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied being 0.50 or more.

The present invention (8) provides the aluminum alloy brazing sheet of(7), wherein the sacrificial anode material further comprises one or twoor more of Mn of (2.0) mass % or less. Mg of 3.00 mass % or less, Si of1.50 mass % or less, Fe of 1.00 mass % or less, Cu of 1.00 mass % orless, Ti of 0.30 mass % or less, Zr of 0.30 mass % or less, Cr of 0.30mass % or less, In of 0.100 mass % or less, and Sn of 0.100 mass % orless.

The present invention (9) provides the aluminum alloy brazing sheet of(7) or (8), wherein the brazing material further comprises one or two ormore of Bi of 1.00 mass % or less. Na of 0.050 mass % or less, Sr of0.050 mass % or less, Mg of 2.00 mass % or less, Zn of 8.00 mass % orless, Cu of 4.00 mass % or less. In of 0.100 mass % or less, Sn of 0.100mass % or less, and Fe of 1.00 mass % or less.

The present invention (10) provides the aluminum alloy brazing sheet ofany one of (7) to (9), wherein the core material further comprises oneor two or more of Ti less than 0.10 mass %, Cu of 1.20 mass % or less,Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less.

The present invention (11) provides a method for manufacturing thealuminum alloy brazing sheet of any one of (1) to (3), the methodcomprising executing at least hot working, cold working, one or moreintermediate annealings between rolling passes in the cold working, andfinal annealing after the last pass of the cold working on a stackedstructure acquired by stacking a brazing material ingot and a corematerial ingot in this order to acquire the aluminum alloy brazingsheet, wherein

the core material ingot is formed of an aluminum alloy comprising Mn of0.50 to 200 mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % orless, and Fe of 100 mass % or less, with the balance being aluminum andinevitable impurities,

the brazing material ingot is formed of an aluminum alloy comprising Siof 4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities, and

a working ratio (working ratio=((t_(a)−t_(b))/t)×100) of a thicknesst_(b) before the final annealing to a thickness t_(a) after the lastintermediate annealing among the intermediate annealings is 20 to 70%.

The present invention (12) provides the method for manufacturing thealuminum alloy brazing sheet of (11), wherein the brazing material ingotfurther comprises one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless.

The present invention (13) provides the method for manufacturing thealuminum alloy brazing sheet of (11) or (12), wherein the core materialingot further comprises one or two or more of Ti less than 0.10 mass %,Cu of 1.20 mass % or less, Zr of 0.30 mass % or less, and Cr of 0.30mass % or less.

The present invention (14) provides a method for manufacturing thealuminum alloy brazing sheet of any one of (4) to (6), the methodcomprising executing at least hot working, cold working, one or moreintermediate annealings between rolling passes in the cold working, andfinal annealing after the last pass of the cold working on a stackedstructure acquired by stacking a brazing material ingot, a core materialingot, and a brazing material ingot in this order to acquire thealuminum alloy brazing sheet, wherein

the core material ingot is formed of an aluminum alloy comprising Mn of0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % orless, and Fe of 1.0 mass % or less, with the balance being aluminum andinevitable impurities.

each of the brazing material ingots is formed of an aluminum alloycomprising Si of 4.00 to 13.00 mass % with the balance being aluminumand inevitable impurities, and

a working ratio (working ratio=t_(a)−t_(b))/t_(a))×100) of a thicknesst_(b) before the final annealing to a thickness t_(a) after the lastintermediate annealing among the intermediate annealings is 20 to 70%.

The present invention (15) provides the method for manufacturing thealuminum alloy brazing sheet of (14), wherein the brazing material ingotfurther comprises one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less. Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless.

The present invention (16) provides the method for manufacturing thealuminum alloy brazing sheet of (14) or (15), wherein the core materialingot further comprises one or two or more of Ti less than 0.10 mass %,Cu of 1.20 mass % or less, Zr of 0.30 mass % or less, and Cr of 0.30mass % or less.

The present invention (17) provides a method for manufacturing thealuminum alloy brazing sheet of any one of (7) to (10), the methodcomprising executing at least hot working, cold working, one or moreintermediate annealings between rolling passes in the cold working, andfinal annealing after the last pass of the cold working on a stackedstructure acquired by stacking a brazing material ingot, a core materialingot, and a sacrificial anode material ingot in this order to acquirethe aluminum alloy brazing sheet, wherein

the core material ingot is formed of an aluminum alloy comprising Mn of0.50 to 2.00 mass %, Mg of 0.40 to 200 mass %, Si of 1.50 mass % orless, and Fe of 1.00 mass % or less, with the balance being aluminum andinevitable impurities.

the brazing material ingot is formed of an aluminum alloy comprising Siof 4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities,

the sacrificial anode material ingot is formed of aluminum or analuminum alloy comprising Zn of 8.00 mass % or less with the balancebeing aluminum and inevitable impurities, and

a working ratio (working ratio=((t_(a)−t_(b))/t_(a))×100) of a thicknessto before the final annealing to a thickness t_(a) after the lastintermediate annealing among the intermediate annealings is 20 to 70%.

The present invention (18) provides the method for manufacturing thealuminum alloy brazing sheet of (17), wherein the sacrificial anodematerial ingot further comprises one or two or more of Mn of 2.00 mass %or less, Mg of 3.00 mass % or less. Si of 1.50 mass % or less, Fe of1.00 mass % or less, Cu of 1.00 mass % or less, Ti of 0.30 mass % orless, Zr of 0.30 mass % or less, Cr of 0.30 mass % or less, In of 0.100mass % or less, and Sn of 0.100 mass % or less.

The present invention (19) provides the method for manufacturing thealuminum alloy brazing sheet of (17) or (18), wherein the brazingmaterial ingot further comprises one or two or more of Bi of 1.00 mass %or less, Na of 0.050 mass % or less, Sr of 0.050 mass % or less, Mg of2.0 mass % or less, Zn of 8.00 mass % or less, Cu of 4.00 mass % orless, in of 0.100 mass % or less, Sn of 0.100 mass % or less, and Fe of1.00 mass % or less.

The present invention (20) provides the method for manufacturing thealuminum alloy brazing sheet of any one of (17) to (19), wherein thecore material ingot further comprises one or two or more of Ti less than0.10 mass %, Cu of 1.20 mass % or less, Zr of 0.30 mass % or less, andCr of 0.30 mass % or less.

The present invention (21) provides the method for manufacturing thealuminum alloy brazing sheet of any one of (11) to (20), wherein a timefor which the structure is maintained at 300° C. or more is three hoursor more, a time for which the structure is maintained at 340° C. or moreis one hour or more, and cooling speed is 300° C./hour or less in theintermediate annealings.

The present invention (22) provides the method for manufacturing thealuminum alloy brazing sheet of any one of (11) to (21), wherein a timefor which the structure is maintained at 300° C. or more is three hoursor more, a time for which the structure is maintained at 340° C. or moreis one hour or more, and cooling speed is 300° C./hour or less in thefinal annealing.

Effects of Invention

The present invention provides an aluminum alloy brazing sheet achievingexcellent brazability. With the aluminum alloy brazing sheet, in thecase of brazing an aluminum material in an inert gas atmosphere, such asa nitrogen gas atmosphere, or in vacuum without using a flux, Mg ispromptly supplied into the brazing material in brazing heating andsufficiently eluted into the molten brazing material after melting ofthe brazing material is started. This enables efficient breakage of theoxide film on the surface of the brazing material, and suppressesdiffusion of Si in the brazing material into the core material inbrazing heating.

BRIEF EXPLANATION OF DRAWINGS

FIG. 1 is a diagram illustrating a miniature core prepared in anexample.

FIG. 2 is a diagram illustrating a state of an aluminum alloy brazingsheet according to a first embodiment of the present invention afterheating in a drop-type fluidity test.

FIG. 3 is a diagram illustrating a state of an aluminum alloy brazingsheet according to a second embodiment of the present invention afterheating in a drop-type fluidity test.

FIG. 4 is a diagram illustrating a state of an aluminum alloy brazingsheet according to a third embodiment of the present invention afterheating in a drop-type fluidity test.

EMBODIMENTS OF INVENTION

<Aluminum Alloy Brazing Sheet according to First Embodiment of PresentInvention>

An aluminum alloy brazing sheet according to the first embodiment of thepresent invention is an aluminum alloy brazing sheet used for brazing ofan aluminum material in an inert gas atmosphere or in vacuum and formedof a two-layer material in which a brazing material and a core materialare stacked in this order.

The core material is formed of an aluminum alloy and has a grain size of20 to 300 μm, the aluminum alloy comprises Mn of 0.50 to 2.00 mass %, Mgof 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of 1.00 mass %or less, with the balance being aluminum and inevitable impurities.

The brazing material is formed of an aluminum alloy comprising Si of4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities.

In a drop-type fluidity test, a ratio α (α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied is 0.50 or more.

The aluminum alloy brazing sheet according to the first embodiment ofthe present invention is formed of a two-layer material in which abrazing material and a core material are stacked in this order.Specifically, the aluminum alloy brazing sheet according to the presentinvention is a clad material in which a brazing material is cladded ontoone side surface of the core material.

The core material of the aluminum alloy brazing sheet according to thefirst embodiment of the present invention is formed of an aluminum alloycomprising Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of1.50 mass % or less, and Fe of 1.00 mass % or less, with the balancebeing aluminum and inevitable impurities.

The core material comprises Mn. Mn included in the core material formsAl—Fe—Mn based, Al—Mn—Si based, and Al—Fe—Mn—Si based intermetalliccompounds together with Fe and Si, and acts to achieve dispersionstrengthening, or is dissolved into the matrix to improve the materialstrength by solid solution strengthening. Mn included in the corematerial also exhibits the effect of setting the potential noble toincrease the difference in potential from the sacrificial anode materialand/or the fin so as to improve the anticorrosion effect by thesacrificial anode effect. The Mn content in the core material is 0.50 to2.00 mass % and preferably 0.60 to 1.50 mass %. When the Mn content inthe core material exceeds the range described above, giant intermetalliccompounds are easily generated in casting and the plastic workability isreduced. By contrast, when the Mn content in the core material is lessthan the range described above, sufficient strength and sufficientanticorrosion effect cannot be acquired.

The core material comprises Mg. Mg included in the core material isdissolved into the matrix to improve the material strength by solidsolution strengthening. In addition, Mg included in the core materialreacts with Si to exhibit the effect for strength improvement by ageprecipitation of the Mg₂Si compound. Besides, because Mg has lower freeenergy of oxide formation than that of aluminum, Mg included in the corematerial is diffused into the brazing material in brazing heating tobreak the oxide film of aluminum covering the surface of the brazingmaterial. The Mg content in the core material is 0.40 to 2.00 mass %,preferably 0.50 to 1.50 mass %, particularly preferably 0.70 to 1.10mass %. By contrast, when the Mg content in the core material is lessthan the range described above, the Mg content diffused and eluted intothe brazing material becomes insufficient, and the effect of breakingthe oxide film on the surface of the brazing material becomesinsufficient. In addition, the Mg content exceeding the range describedabove lowers the solidus temperature (melting point) of the corematerial, and increases the possibility of causing melting of the corematerial in brazing.

The core material comprises Si. Si included in the core material formsAl—Mn—Si based, Al—Fe—Si based, and Al—Fe—Mn—Si based compounds togetherwith Fe and Mn, and acts to achieve dispersion strengthening, or isdissolved into the matrix to improve the material strength by solidsolution strengthening. In addition, Si included in the core materialreacts with Mg to exhibit the effect for strength improvement by ageprecipitation of the Mg₂Si compound. The Si content in the core materialis 1.50 mass % or less, preferably 0.05 to 1.50 mass %, and particularlypreferably 0.20 to 1.00 mass %. The Si content in the core materialexceeding the range described above lowers the solidus temperature(melting point) of the core material, and increases the possibility ofcausing melting of the core material in brazing.

The core material comprises Fe. Fe included in the core material formsAl—Fe—Mn based, Al—Fe—Si based, and Al—Fe—Mn—Si based compounds togetherwith Mn and Si, acts to achieve dispersion strengthening, and improvesthe material strength. The Fe content in the core material is 1.00 mass% or less, preferably 0.05 to 1.00 mass %, and particularly preferably0.05 to 0.70 mass %. When the Fe content in the core material exceedsthe range described above, giant intermetallic compounds are easilygenerated in casting and the plastic workability is reduced.

The core material may further comprise one or two or more of Ti, Cu, Zr,and Cr.

Ti included in the core material miniaturizes the grain size of theingot in casting, and suppresses casting cracks. When the core materialcomprises Ti, the Ti content in the core material is less than 0.10 mass% and preferably 0.05 mass % or more and less than 0.10 mass %.

Cu included in the core material improves the material strength by solidsolution strengthening. Cu included in the core material also exhibitsthe effect of setting the potential noble to increase the difference inpotential from the sacrificial anode material and/or the fin so as toimprove the anticorrosion effect by the sacrificial anode effect. Whenthe core material comprises Cu, the Cu content in the core material is1.20 mass % or less and preferably 0.05 to 0.80 mass %. The Cu contentin the core material exceeding the range described above increases thepossibility of occurrence of intergranular corrosion, and increases thepossibility of melting of the core material due to decrease in meltingpoint thereof.

Zr included in the core material improves strength by solid solutionstrengthening, and precipitates Al—Zr based minute compounds to act ongrain coarsening after brazing. When the core material comprises Zr, theZr content in the core material is 0.30 mass % or less and preferably0.10 to 0.20 mass %. When the Zr content in the core material exceedsthe range described above, giant intermetallic compounds are easilyformed in casting, and plastic workability is reduced.

Cr included in the core material improves strength by solid solutionstrengthening, and precipitates Al—Cr based minute compounds to act ongrain coarsening after brazing. When the core material comprises Cr, theCr content in the core material is 0.30 mass % or less and preferably0.10 to 0.20 mass %. When the Cr content in the core material exceedsthe range described above, giant intermetallic compounds are easilyformed in casting, and plastic workability is reduced.

The grain size of the core material is 20 to 300 μm and preferably 50 to200 μm. With the grain size of the core material falling within therange described above, excellent brazability is achieved. When the grainsize of the core material is small, Si included in the brazing materialdirectly cladded onto the core material is easily diffused in thevicinity of the grain boundary of the core material. This decreases thebrazing material quantity and lowers the brazability. When the grainsize of the core material is large, the diffusion quantity of Si issuppressed. The grain size of the core material less than the rangedescribed above lowers the brazability. The grain size exceeding therange described above causes a rough surface when the aluminum alloybrazing sheet is subjected to plastic working. The grain size of thecore material can be set to the range described above by setting theworking ratio (working ratio=((t_(a)−t_(b))/t_(a))×100) of a thicknesst_(b) before the final annealing to a thickness to after the lastintermediate annealing among intermediate annealings executed betweenpasses of cold working to 20 to 70%, in the manufacturing process of thealuminum alloy brazing sheet. In addition, in the intermediate annealingor the final annealing, the time for which the structure is maintainedat 300° C. or more is three hours or more, the time for which thestructure is maintained at 340° C. or more is one hour or more, andcooling speed is 30) ° C./hour or less. This lowers the solid solubilityof Mg, suppresses collection of transfer at the time when a 5% strain isapplied before brazing, and suppresses miniaturization of the grainsize.

The brazing material of the aluminum alloy brazing sheet according tothe first embodiment of the present invention is formed of an aluminumalloy comprising Si of 4.00 to 13.00 mass % with the balance beingaluminum and inevitable impurities.

The Si content in the brazing material is 4.00 to 13.00 mass %. When theSi content in the brazing material is less than the range describedabove, no sufficient brazability is acquired. The Si content exceedingthe range described above causes easy formation of coarse proeutectic Siin casting, causes easy occurrence of cracks in manufacturing of thematerial, and lowers plastic workability.

The brazing material may further comprise Bi. Bi included in the brazingmaterial promotes breakage of the oxide film with Mg supplied from thecore material to the brazing material in brazing heating, and improvesthe brazability. When the brazing material comprises Bi, the Bi contentin the brazing material is 1.00 mass % or less and preferably 0.004 to0.50 mass %. The Bi content in the brazing material exceeding the rangedescribed above causes cracks in hot rolling, and causes difficulty inmanufacturing.

The brazing material may further comprise one or two of Na and Sr. Na orSr is added to the brazing material to miniaturize the Si particles.When the brazing material comprises Na, the Na content in the brazingmaterial is 0.050 mass % or less, preferably 0.003 to 0.050 mass %, andparticularly preferably 0.005 to 0.030 mass %. When the brazing materialcomprises Sr, the Sr content in the brazing material is 0.050 mass % orless, preferably 0.003 to 0.050 mass %, and particularly preferably0.005 to 0.030 mass %.

The brazing material may further comprise Mg. Mg in the brazing materialbreaks an aluminum oxide film covering the surface of the brazingmaterial, and improves the brazability. When the brazing materialcomprises Mg, the Mg content in the brazing material is 2.00 mass % orless, and preferably 0.01 to 1.00 mass %. When the Mg content in thebrazing material exceeds the range described above, MgO is formed on thesurface of the brazing material before the brazing material is moltenduring brazing heating, and the brazability is lowered.

The brazing material may further comprise one or two of Zn and Cu. Znand Cu in the brazing material lowers the melting point of the brazingmaterial, and enables brazing at a temperature lower than 600° C.serving as an ordinary brazing temperature. When the brazing materialcomprises Zn, the Zn content in the brazing material is 8.00 mass % orless, preferably 0.50 to 8.00 mass %, and particularly preferably 2.00to 4.00 mass %. When the brazing material comprises Cu, the Cu contentin the brazing material is 4.00 mass % or less and preferably 1.00 to3.00 mass %.

The brazing material may further comprise one or two of In and Sn. Inand Sn in the brazing material sets the natural potential of thematerial lessnoble, and exhibits the sacrificial anticorrosion effect.When the brazing material comprises in, the In content in the brazingmaterial is 0.100 mass % or less, preferably 0.005 to 0.100 mass %, andparticularly preferably 0.010 to 0.050 mass %. When the brazing materialcomprises Sn, the Sn content in the brazing material is 0.100 mass % orless, preferably 0.005 to 0.100 mass %, and particularly preferably0.010 to 0.050 mass %.

The brazing material may further comprise Fe of 1.00 mass % or less, andpreferably 0.05 to 0.50 mass %.

The aluminum alloy brazing sheet according to the first embodiment ofthe present invention has a structure in which, in a drop-type fluiditytest, a ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a) after a 5%strain is applied to a fluid coefficient K_(b) before the strain isapplied is 0.50 or more and preferably 0.60 or more. In a drop-typefluidity test, when the ratio α (α=K_(a)/K_(b)) of a fluid coefficientK_(a) after a 5% strain is applied to a fluid coefficient K_(b) beforethe strain is applied falls within the range described above, erosionrarely occurs in brazing heating. By contrast, in a drop-type fluiditytest, when the ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a)after a 5% strain is applied to a fluid coefficient K_(b) before thestrain is applied is less than the range described above, erosion occursin brazing heating. The method for measuring the ratio α (α=K_(a)/K_(b))of the fluid coefficient K_(a) after a 5% strain is applied to the fluidcoefficient K_(b) before the strain is applied in a drop-type fluiditytest will be described later.

<Aluminum Alloy Brazing Sheet according to Second Embodiment of PresentInvention>

An aluminum alloy brazing sheet according to the second embodiment ofthe present invention is an aluminum alloy brazing sheet used forbrazing of an aluminum material in an inert gas atmosphere or in vacuumand formed of a three-layer material in which a brazing material, a corematerial, and a brazing material are stacked in this order.

The core material is formed of an aluminum alloy and has a grain size of20 to 300 μm, the aluminum alloy comprises Mn of 0.50 to 2.00 mass %, Mgof 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of 1.00 mass %or less, with the balance being aluminum and inevitable impurities.

Each of the brazing materials is formed of an aluminum alloy comprisingSi of 4.00 to 13.00 mass % with the balance being aluminum andinevitable impurities.

In a drop-type fluidity test, a ratio α (α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied is 0.50 or more.

The aluminum alloy brazing sheet according to the second embodiment ofthe present invention is formed of a three-layer material in which abrazing material 1, a core material, and a brazing material 2 arestacked in this order. Specifically, the aluminum alloy brazing sheetaccording to the second embodiment of the present invention is a cladmaterial in which the brazing material 1 is cladded onto one sidesurface of the core material and the brazing material 2 is cladded ontothe other side surface of the core material. In the aluminum alloybrazing sheet according to the second embodiment of the presentinvention, the brazing material 1 and the brazing material 2 may havethe same chemical composition or different chemical compositions.

The core material and the brazing materials (brazing material 1 andbrazing material 2) according to the aluminum alloy brazing sheetaccording to the second embodiment of the present invention are the sameas the core material and the brazing material of the aluminum alloybrazing sheet according to the first embodiment of the presentinvention.

The aluminum alloy brazing sheet according to the second embodiment ofthe present invention has a structure in which, in a drop-type fluiditytest, a ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a) after a 5%strain is applied to a fluid coefficient K_(b) before the strain isapplied is 0.50 or more and preferably 0.60 or more. Ina drop-typefluidity test, when the ratio α (α=K_(a)/K_(b)) of a fluid coefficientK_(a) after a 5% strain is applied to a fluid coefficient K_(b) beforethe strain is applied falls within the range described above, erosionrarely occurs in brazing heating. By contrast, in a drop-type fluiditytest, when the ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a)after a 5% strain is applied to a fluid coefficient K_(b) before thestrain is applied is less than the range described above, erosion occursin brazing heating. The method for measuring the ratio α (α=K_(a)/K_(b))of the fluid coefficient K_(a) after a 5% strain is applied to the fluidcoefficient K_(b) before the strain is applied in a drop-type fluiditytest will be described later.

The aluminum alloy brazing sheet according to the third embodiment ofthe present invention is an aluminum alloy brazing sheet used forbrazing of an aluminum material in an inert gas atmosphere or in vacuumand formed of a three-layer material in which a brazing material, a corematerial, and a sacrificial anode material are stacked in this order.

The core material is formed of an aluminum alloy and has a grain size of20 to 300 μm, the aluminum alloy comprises Mn of 0.50 to 2.00 mass %, Mgof 0.40 to 2.00 mass %, Si of 1.50 mass % or less, and Fe of 1.00 mass %or less, with the balance being aluminum and inevitable impurities.

The brazing material is formed of an aluminum alloy comprising Si of4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities.

The sacrificial anode material is formed of aluminum or an aluminumalloy comprising Zn of 8.00 mass % or less with the balance beingaluminum and inevitable impurities.

In a drop-type fluidity test, a ratio α (α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied is 0.50 or more.

<Aluminum Alloy Brazing Sheet according to Third Embodiment of PresentInvention>

An aluminum alloy brazing sheet according to the third embodiment of thepresent invention is formed of a three-layer material in which a brazingmaterial, a core material, and a sacrificial anode material are stackedin this order. Specifically, the aluminum alloy brazing sheet accordingto the third embodiment of the present invention is a clad material inwhich the brazing material is cladded onto one side surface of the corematerial and the sacrificial anode material is cladded onto the otherside surface of the core material.

The core material and the brazing material according to the aluminumalloy brazing sheet according to the third embodiment of the presentinvention are the same as the core material and the brazing material ofthe aluminum alloy brazing sheet according to the first embodiment ofthe present invention.

The sacrificial anode material of the aluminum alloy brazing sheetaccording to the third embodiment of the present invention is formed ofaluminum or an aluminum alloy comprising Zn of 8.00 mass % or less withthe balance being aluminum and inevitable impurities.

The purity of the aluminum of the sacrificial anode material is notparticularly limited, but preferably 99.0 mass % or more andparticularly preferably 99.5 mass % or more.

The aluminum alloy of the sacrificial anode material comprises Zn. Znincluded in the sacrificial anode material has the effect of setting thepotential lessnoble, and exhibits the sacrificial anticorrosion effectby forming a difference in potential between the sacrificial anodematerial and the core material. The Zn content in the sacrificial anodematerial is 8.00 mass % or less and preferably 3.00 mass % or less.

The aluminum alloy of the sacrificial anode material may comprise Mg. Mgincluded in the sacrificial anode material is diffused into the brazingmaterial in brazing heating to break the aluminum oxide film coveringthe surface of the brazing material and improves the brazability, whenthe sacrificial anode material serves as the joining surface. The Mgcontent in the sacrificial anode material is 3.00 mass % or less andpreferably 0.50 to 2.50 mass %. By contrast, when the Mg content in thesacrificial anode exceeds the range described above, a MgO oxide film isgenerated, and the brazability decreases.

The aluminum alloy of the sacrificial anode material may comprise one ortwo or more of Mn, Si, Fe, Cu, Ti, Zr, and Cr.

Mn, Si, Fe, Cu, Ti, Zr, and Cr included in the sacrificial anodematerial form intermetallic compounds to act as dispersion strengtheningelements, or dissolved into the matrix to act as solid solutionstrengthening elements. When the sacrificial anode material comprisesMn, the Mn content in the sacrificial anode material is 2.00 mass % orless and preferably 0.30 to 1.50 mass %. When the sacrificial anodematerial comprises Si, the Si content in the sacrificial anode materialis 1.50 mass % or less and preferably 0.20 to 1.00 mass %. When thesacrificial anode material comprises Fe, the Fe content in thesacrificial anode material is 1.00 mass % or less and preferably 0.05 to0.70 mass %. When the sacrificial anode material comprises Cu, the Cucontent in the sacrificial anode material is 1.00 mass % or less andpreferably 0.01 to 0.30 mass %. When the sacrificial anode materialcomprises Ti, the Ti content in the sacrificial anode material is 0.30mass % or less and preferably 0.10 to 0.20 mass %. When the sacrificialanode material comprises Zr, the Zr content in the sacrificial anodematerial is 0.30 mass % or less and preferably 0.10 to 0.20 mass %. Whenthe sacrificial anode material comprises Cr, the Cr content in thesacrificial anode material is 0.30 mass % or less and preferably 0.10 to0.20 mass %.

The sacrificial anode material may further comprise one or two of In andSn. In and Sn in the sacrificial anode material have the effect ofsetting the natural potential of the material lessnoble, and exhibitsthe sacrificial anticorrosion effect. When the sacrificial anodematerial comprises In, the In content in the sacrificial anode materialis 0.100 mass % or less, preferably 0.005 to 0.100 mass %, andparticularly preferably 0.010 to 0.050 mass %. When the sacrificialanode material comprises Sn, the Sn content in the sacrificial anodematerial is 0.100 mass % or less, preferably 0.005 to 0.100 mass %, andparticularly preferably 0.010 to 0.050 mass %.

The aluminum alloy brazing sheet according to the third embodiment ofthe present invention has a structure in which, in a drop-type fluiditytest, a ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a) after a 5%strain is applied to a fluid coefficient K_(b) before the strain isapplied is 0.50 or more and preferably 0.60 or more. Ina drop-typefluidity test, when the ratio α (α=K_(a)/K_(b)) of a fluid coefficientK_(a) after a 5% strain is applied to a fluid coefficient K_(b) beforethe strain is applied falls within the range described above, erosionrarely occurs in brazing heating. By contrast, in a drop-type fluiditytest, when the ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a)after a 5% strain is applied to a fluid coefficient K_(b) before thestrain is applied is less than the range described above, erosion occursin brazing heating. The method for measuring the ratio α (α=K_(a)/K_(b))of the fluid coefficient K_(a) after a 5% strain is applied to the fluidcoefficient K_(b) before the strain is applied in a drop-type fluiditytest will be described later.

The aluminum alloy brazing sheet according to the first embodiment ofthe present invention, the aluminum alloy brazing sheet according to thesecond embodiment of the present invention, and the aluminum alloybrazing sheet according to the third embodiment of the present inventionare suitably used for brazing the aluminum material in an inert gasatmosphere, such as a nitrogen gas atmosphere, or in vacuum withoutusing a flux. The aluminum alloy brazing sheet according to the firstembodiment of the present invention, the aluminum alloy brazing sheetaccording to the second embodiment of the present invention, and thealuminum alloy brazing sheet according to the third embodiment of thepresent invention are used for tubes serving as channel formingmaterials through which the coolant or the like flow, and/or platesjoined with the tubes to form the structures of heat exchangers. Whenthe aluminum alloy brazing sheet according to the first embodiment ofthe present invention, the aluminum alloy brazing sheet according to thesecond embodiment of the present invention, or the aluminum alloybrazing sheet according to the third embodiment of the present inventionis used for the tube material, the thickness of the brazing sheet isapproximately 0.15 to 0.5 mm, and the clad ratio of the brazing materialor the sacrificial anode material is generally approximately 5 to 30%.When the aluminum alloy brazing sheet according to the first embodimentof the present invention, the aluminum alloy brazing sheet according tothe second embodiment of the present invention, or the aluminum alloybrazing sheet according to the third embodiment of the present inventionis used for the plate material, the thickness of the brazing sheet isapproximately 0.8 to 5 mm, and the clad ratio of the brazing material orthe sacrificial anode material is generally approximately 5 to 30%.

When the core material of the aluminum alloy brazing sheet comprises Mg,the solidus temperature of the core material is low. In addition, when astrain is applied to the aluminum alloy brazing sheet before brazingheating, recrystallization occurs in brazing heating. Although the grainsize becomes coarse, because subgrains remain and Si is infiltrated intothe subgrain boundary of the subgrains, erosion easily occurs. For thisreason, in the process of manufacturing the aluminum alloy brazingsheet, the processing ratio before final annealing is reduced tooptimize the grain size of the material, and the heat input at and afterhot working is increased to coarsen the fine Mn-based compound. Inaddition, Mg is precipitated to increase the recrystallizationtemperature and increase the recrystallization grain size in brazingheating, and generation of subgrains is suppressed. With this structure,erosion is suppressed. In addition, the inventors of the presentinvention have found that: (I) the aluminum alloy brazing sheet inwhich, in a drop-type fluidity test, a ratio α (α=K_(a)/K_(b)) of afluid coefficient K after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied is 0.50 or more and preferably 0.60or more is obtained, by setting the working ratio before final annealingto 20 to 70% in the manufacturing process of the aluminum alloy brazingsheet, specifically, by setting a working ratio (workingratio=((t_(a)−t_(b))/×100) of a thickness t_(b) before the finalannealing to a thickness t_(a) after the last intermediate annealingamong the intermediate annealings executed between passes of coldrolling in the cold working to 20 to 70%; and (M) in the aluminum alloybrazing sheet in which, in a drop-type fluidity test, a ratio α(α=K_(a)/K_(b)) of a fluid coefficient K_(a) after a 5% strain isapplied to a fluid coefficient K_(b) before the strain is applied is0.50 or more and preferably 0.60 or more, erosion rarely occurs evenwhen a strain is applied when the aluminum alloy brazing sheet isprocessed into a predetermined shape before brazing, that is, erosion inbrazing heating is suppressed by setting, in a drop-type fluidity test,“a ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a) after a 5%strain is applied to a fluid coefficient K_(b) before the strain isapplied” to 0.50 or more and preferably 0.60 or more.

In the aluminum alloy brazing sheet according to the present invention,a ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a) after a 5% strainis applied to a fluid coefficient K_(b) before the strain is applied canbe determined by the following process. Two aluminum alloy brazingsheets (before a strain is applied) serving as test materials areprepared, a 5% strain is applied to one of the sheets by cold rolling toprepare a test material provided with a 5% strain. Applying a 5% strainby cold rolling means that the test material is subjected to processingto reduce the thickness of the test material by a thicknesscorresponding to 5% of the thickness thereof at the time before thestrain is applied. For example, when the thickness of the test materialbefore the strain is applied is 0.5) mm, a strain in the case whereprocessing is executed to reduce the thickness to 0.475 mm by coldrolling is 5%. Thereafter, fluid coefficients of the test materials aredetermined by a drop-type fluidity test using the test material before astrain is applied and the test material provided with the 5% strain.Each of the test materials is cut to a size of 40 mm (width)×60 mm(length), with the rolling direction serving as the longitudinaldirection, and provided with two hanging holes 3 φ, and thereafterweight (W0) thereof is measured. Thereafter, the test materials are hungas illustrated in FIG. 2 (the aluminum alloy brazing sheet according tothe first embodiment of the present invention), FIG. 3 (the aluminumalloy brazing sheet according to the second embodiment of the presentinvention), and FIG. 4 (the aluminum alloy brazing sheet according tothe third embodiment of the present invention), heated to a maximumtemperature of 600° C. with an average temperature increase speed of 20°C./min from the room temperature to 600° C. in a nitrogen gas furnace(oxygen concentration: 15 to 20 ppm), and maintained for three minutesat 600° C. After heating, as illustrated in FIG. 2 (the aluminum alloybrazing sheet according to the first embodiment of the presentinvention), FIG. 3 (the aluminum alloy brazing sheet according to thesecond embodiment of the present invention), and FIG. 4 (the aluminumalloy brazing sheet according to the third embodiment of the presentinvention), the brazing material storing portion (B) is cut to measurethe weight (WB) thereof, and the fluid coefficient (K) is determined by:

K=(4WB−W0)/(3W0×clad ratio)  (1)

The fluid coefficient (K_(b)) of the test material before the strain isapplied and the fluid coefficient (K_(a)) after the 5% strain is appliedare determined, and the ratio α (α=K_(a)/K_(b)) of the fluid coefficientK after the 5% strain is applied to the fluid coefficient Kh before thestrain is applied is calculated by:

α=K _(a) /K _(b)  (2).

In the aluminum alloy brazing sheet according to the second embodimentof the present invention, when the brazing material 1 side and thebrazing material 2 side have different fluid coefficients because of thedifference in composition between the brazing material 1 and the brazingmaterial 2, the fluid coefficient ratio α is determined as a mean valueof the brazing material 1 side and the brazing material 2 side.

The following is an explanation of a method for manufacturing thealuminum alloy brazing sheet according to the present invention. Themethod for manufacturing the aluminum alloy brazing sheet according tothe present invention is a method for manufacturing the aluminum alloybrazing sheet, by executing at least hot working, cold working, one ormore intermediate annealings between rolling passes in the cold working,and final annealing after the last pass of the cold working on a stackedstructure acquired by stacking a brazing material ingot and a corematerial ingot in this order to acquire the aluminum alloy brazing sheetin the method according to the first embodiment of the presentinvention, by stacking a brazing material ingot, a core material ingot,and a brazing material ingot in this order to acquire the aluminum alloybrazing sheet in the method according to the second embodiment of thepresent invention, and by stacking a brazing material ingot, a corematerial ingot, and a sacrificial anode material ingot in this order toacquire the aluminum alloy brazing sheet in the method according to thethird embodiment of the present invention, wherein

a working ratio (working ratio=((t _(a) −t _(b))/t _(a))×100) of athickness t _(b) before the final annealing to a thickness t _(a) afterthe last intermediate annealing among the intermediate annealings is 20to 7%.

Specifically, the method according to the first embodiment of thepresent invention, the method according to the second embodiment of thepresent invention, and the method according to the third embodiment ofthe present invention are the same except that the stacked structuressubjected to hot rolling are different. In the following explanation,for the same points between the embodiments, the method according to thefirst embodiment of the present invention, the method according to thesecond embodiment of the present invention, and the method according tothe third embodiment of the present invention are generally referred toas “method (for manufacturing the aluminum alloy brazing sheet)according to the present invention”.

The method for manufacturing the aluminum alloy brazing sheet accordingto the present invention is a method for manufacturing the aluminumalloy brazing sheet, by executing at least hot working, cold working,one or more intermediate annealings between rolling passes in the coldworking, and final annealing after the last pass of the cold working ona stacked structure acquired by stacking predetermined ingots in apredetermined order.

In the method for manufacturing the aluminum alloy brazing sheetaccording to the present invention, first, aluminum alloys havingdesired compositions used for the core material, the brazing material,and/or the sacrificial anode material are melted and casted to prepare acore material ingot, a brazing material ingot, and/or a sacrificialanode material ingot. The methods for melting and casting the aluminumalloys are not particularly limited, but ordinary methods are used.

Thereafter, the core material ingot, the brazing material ingot, and/orthe sacrificial anode material ingot are homogenized, if necessary. Thepreferred temperature range of homogenization is 400 to 600° C., and thehomogenization time is 2 to 20 hours.

Thereafter, the core material ingot, the brazing material ingot, and/orthe sacrificial anode material ingot are faced to predeterminedthicknesses, and the predetermined ingots are stacked in thepredetermined order to acquire a stacked structure.

The core material ingot is formed of an aluminum alloy comprising Mn of0.50 to 2.00 mass % and preferably 0.60 to 1.50 mass %, Mg of 0.40 to2.00 mass %, preferably 0.50 to 1.50 mass %, and particularly preferably0.70 to 1.10 mass %, Si of 1.50 mass % or less, preferably 0.05 to 1.50mass %, and particularly preferably 0.20 to 1.00 mass %, and Fe of 1.00mass % or less, preferably 0.05 to 1.00 mass %, and particularlypreferably 0.05 to 0.70 mass %, with the balance being aluminum andinevitable impurities.

The core material ingot may further comprise one or two or more of Tiless than 0.10 mass %, Cu of 1.20 mass % or less and preferably 0.05 to0.80 mass %, Zr of 0.30 mass % or less and preferably 0.10 to 0.20 mass%, and Cr of 0.30 mass % or less and preferably 0.10 to 0.20 mass %,

The brazing material ingot is formed of an aluminum alloy comprising Siof 4.00 to 13.00 mass % with the balance being aluminum and inevitableimpurities.

The brazing material ingot may further comprise Bi of 1.00 mass % orless and preferably 0.004 to 0.50 mass %.

The brazing material ingot may further comprise one or two or more of Naof 0.050 mass % or less, preferably 0.003 to 0.050 mass %, andparticularly preferably 0.005 to 0.030 mass %, and Sr of 0.050 mass % orless, preferably 0.003 to 0.050 mass %, and particularly preferably0.005 to 0.030 mass %.

The brazing material ingot may further comprise Mg of 2.00 mass % orless and preferably 0.01 to 1.00 mass %.

The brazing material ingot may further comprise one or two of Zn of 8.00mass % or less, preferably 0.50 to 8.00 mass %, and particularlypreferably 2.00 to 4.00 mass %, and Cu of 4.00 mass % or less andpreferably 1.00 to 3.00 mass %.

The brazing material ingot may further comprise one or two of in of0.100 mass % or less, preferably 0.005 to 0.100 mass %, and particularlypreferably 0.010 to 0.050 mass %, and Sn of 0.100 mass % or less,preferably 0.005 to 0.100 mass %, and particularly preferably 0.010 to0.050 mass %.

The brazing material ingot may further comprise Fe of 1.00 mass % orless and preferably 0.05 to 0.50 mass %.

The sacrificial anode material ingot is formed of aluminum or analuminum alloy comprising Zn of 8.00 mass % or less and preferably 3.00mass % or less, with the balance being aluminum and inevitableimpurities.

The sacrificial anode material ingot may further comprise Mg of 3.00mass % or less and preferably 0.50 to 2.50 mass %.

The sacrificial anode material ingot may further comprise one or two ormore of Mn of 2.00 mass % or less and preferably 0.30 to 1.50 mass %, Siof 1.50 mass % or less and preferably 0.20 to 1.00 mass %, Fe of 1.00mass % or less and preferably 0.05 to 0.70 mass %, Cu of 1.00 mass % orless and preferably 0.01 to 0.30 mass %, Ti of 0.30 mass % or less andpreferably 0.10 to 0.20 mass %, Zr of 0.30 mass % or less and preferably0.10 to 0.20 mass %, and Cr of 0.30 mass % or less and preferably 0.10to 0.20 mass %.

The sacrificial anode material ingot may further comprise one or two ofIn of 0.100 mass % or less, preferably 0.005 to 0.100 mass %, andparticularly preferably 0.010 to 0.050 mass %, and Sn of 0.100 mass % orless, preferably 0.005 to 0.100 mass %, and particularly preferably0.010 to 0.050 mass %.

In the hot working, the stacked structure acquired by stackingpredetermined ingots in the predetermined order is subjected to hotrolling at 400 to 550° C. In hot rolling, the stacked structure isrolled to a thickness of, for example, 2 to 8 mm.

In the cold working, the hot-rolled structure acquired by executing hotworking is subjected to cold rolling. In the cold working, cold rollingis executed with a plurality of passes.

In the cold working, one or two or more times of intermediate annealingare executed between passes of cold rolling. The temperature of theintermediate annealing is 200 to 500° C. and preferably 250 to 400° C.In the intermediate annealing, the temperature is increased to theintermediate annealing temperature, and cooling may be promptly startedafter the temperature reaches the intermediate annealing temperature, orcooling may be started after the structure is maintained for certaintime at the intermediate annealing temperature after the temperaturereaches the intermediate annealing temperature. The time for which thetemperature is maintained at the intermediate annealing temperature is 0to 10 hours and preferably 1 to 5 hours.

After cold rolling, the cold-rolled structure acquired by cold workingis subjected to final annealing to anneal the cold-rolled structure at300 to 500° C. and preferably 350 to 450° C. In the final annealing, thetemperature is increased to the final annealing temperature, and coolingmay be promptly started after the temperature reaches the finalannealing temperature, or cooling may be started after the structure ismaintained for certain time at the final annealing temperature after thetemperature reaches the final annealing temperature. The time for whichthe temperature is maintained at the final annealing temperature is 0 to10 hours and preferably 1 to 5 hours.

In addition, in the method for manufacturing the aluminum alloy cladmaterial according to the present invention, a working ratio (workingratio=((t_(a)−t_(b))/t_(a))×100) of a thickness t_(b) before the finalannealing to a thickness t_(a) after the last intermediate annealingamong the intermediate annealings is 20 to 70%. Specifically, in themethod for manufacturing the aluminum alloy clad material according tothe present invention, after the last intermediate annealing isexecuted, cold working is executed such that the working ratio (workingratio=((t_(a)−t_(b))/t_(a))×100) is set to 20 to 70% in cold rollingbefore the final annealing. By setting the working ratio (workingratio=((t_(a)−t_(b))/t_(a))×100) of a thickness t b before the finalannealing to a thickness t_(a) after the last intermediate annealing to20 to 70%, the grain size of the core material is adjusted to 20 to 300μm and preferably 50 to 200 μm.

In the method for manufacturing the aluminum alloy clad materialaccording to the present invention, to coarsen the grains of the corematerial, it is preferable that the time for which the structure ismaintained at 300° C. or more is three hours or more, the time for whichthe structure is maintained at 340° C. or more is one hour or more, andthe cooling speed is 300° C./hour or less, in the intermediateannealings.

In the method for manufacturing the aluminum alloy clad materialaccording to the present invention, to coarsen the grains of the corematerial, it is preferable that the time for which the structure ismaintained at 300° C. or more is three hours or more, the time for whichthe structure is maintained at 340° C. or more is one hour or more, andthe cooling speed is 300° C./hour or less, in the final annealing.

The aluminum alloy clad material of the present invention is acquired byexecuting the method for manufacturing the aluminum alloy clad materialaccording to the present invention as described above.

An example will be illustrated hereinafter to specifically explain thepresent invention, but the present invention is not limited to theexample illustrated hereinafter.

Example

By continuous casting, the brazing material ingots, the sacrificialanode material ingots, and the core material ingots having the chemicalcompositions illustrated in Table 1 are prepared. Thereafter, the corematerial ingots are homogenized and thereafter subjected to facing toreduce the thickness of the core material ingots to a predeterminedthickness. Thereafter, the brazing material ingots and the sacrificialanode material ingots are subjected to hot rolling to set thethicknesses of the brazing material ingots and the sacrificial anodematerial ingots to predetermined thicknesses. The brazing materialingots, the sacrificial anode material ingots, and the core materialingots acquired as described above are superimposed with combinations asillustrated in Table 1 to prepare stacked structures. Each of theacquired stacked structures is hot-rolled to join the core materialingot and the brazing material ingot or the sacrificial anode materialingot and prepare a clad material having a thickness of 3.0 mm. Each ofthe acquired clad materials was subjected to cold rolling, intermediateannealing, cold rolling, and final annealing in this order to acquire atest material having a thickness of 0.5 mm. The intermediate annealingand the final annealing were executed at a retaining temperature of 400°C. and with the retaining time of three hours. Table 2 illustrates theworking ratio (working ratio=((t_(a)−t_(b))/t_(a))×100) from a thickness(t_(a)) after the intermediate annealing to a thickness (t_(b)) beforethe final annealing and the annealing conditions. In the cooling speedserving as the annealing condition, A denotes the speed “50° C./hour ormore and less than 150° C./hour”, B denotes the speed “150° C./hour ormore and 300° C./hour or less”, and X denotes the speed exceeding 300°C./hour.

<Measurement of Grain Size>

The cross section (L-LT face) of each of the prepared test materials issubjected to mirror polishing to execute surface shaping, thereafter,subjected to barker etching, and a photomicrograph is taken. In thephotomicrograph, a line segment parallel with an interface between thebrazing material and the core material was drawn on the core material,the number of grains cut with the line segment was counted, and thegrain size of the core material was calculated with the calculationformula “grain size (μm)=(length of line segment (mm)×1000))/(number ofcut grains×photograph magnifications)”. Suppose that the number ofgrains at the end portion of the line segment is 0.5. Table 2illustrates the grain size of the core material. In Table 2, X denotesthe grain size exceeding 300 μm, A denotes the grain size equal to orless than 300 μm and equal to or more than 100 μm, B denotes the grainsize less than 100 μm and equal to or more than 20 μm, and Y denotes thegrain size less than 20 μm.

<Evaluation of Brazability>

The test material having a size of 50 mm×50 mm and subjected to onlydegreasing with acetone (not etched), the test material subjected todegreasing with acetone and thereafter etched with weak acid (etched),and a 3003 alloy plate material having a thickness of 0.1 mm, subjectedto corrugating, and thereafter degreased were prepared, and mounted onthe miniature core illustrated in FIG. 1.

Thereafter, brazing heating was executed in a nitrogen gas furnace. Thenitrogen gas furnace is a batch-type experimental furnace. The oxygenconcentration in brazing was set to 15 to 20 ppm. The maximumtemperature of each of the test pieces was set to 600° C.

Thereafter, the corrugated fin was cut off from the miniature core afterbrazing. Thereafter, the lengths of the traces of the fillets existingon each plate were measured in the width direction of the plate, and thesum of them was calculated. Apart from it, the sum of lengths of thefillets in the width direction in the case where it is supposed that theplate and the corrugated fin were entirely joined is calculated. Inaddition, the ratio of the former value to the latter value is regardedas the joining ratio (%) of the corrugated fin in each test member. Thelatter value can be calculated by, for example, multiplying the width ofthe corrugated fin by the number of top portions of the corrugated fin.The joining ratio was calculated for each of the upper test material andthe lower test material.

The test material of 0.5 mm acquired by the above process and the testmaterial (5% strain) acquired by rolling the test material acquired bythe above processing and having a thickness of 0.5 mm to a thickness of0.475 mm by cold rolling were subjected to a drop-type fluidity test todetermine the fluid coefficients of them.

First, each of the test materials was cut to a size of 40 mm (width)×60mm (length), with the rolling direction serving as the longitudinaldirection, and provided with two hanging holes 3φ, and thereafter weight(W0) thereof is measured. Thereafter, the test materials were hung asillustrated in FIG. 2, FIG. 3, or FIG. 4, heated to a maximumtemperature of 600° C. with an average temperature increase speed of 20°C./min from the room temperature to 600° C. in a nitrogen gas furnace,and maintained for three minutes at 600° C. After the heating test, thebrazing material storing portion (B) was cut to measure the weight (WB)thereof, and the fluid coefficient (K) was determined by:

K=(4WB−W0)/(3W0×clad ratio)  (1).

Thereafter, the ratio α of the fluid coefficient K_(a) after the 5%strain was applied to the fluid coefficient K_(a) before the strain wasapplied was calculated by:

α=K _(a) /K _(b)  (2).

Table 2 illustrates the value of α. In Table 2, A denotes α having thevalue of 0.70 or more, B denotes α having the value less than 0.70 andequal to or more than 0.50, and X denotes α having the value less than0.50.

In the item “brazing results of miniature core test materials” in Table1, “good” denotes the case where both joining ratio of the upper testmaterial and joining ratio of the lower test material were 80% or more,and “fail” denotes the case where the joining ratios were less than 80%,as a result of executing brazing for the miniature core test materials.In evaluation of brazability of the present example, the case where theaverage of the joining ratios is 80% or more is determined as anacceptable material because it has excellent brazability. In addition,the case where the average of the joining ratios is less than 80% isdetermined as a non-acceptable material because it has poor brazability.

TABLE 1 TEST CLAD MATERIAL CLAD CHEMICAL COMPOSITION (mass %) RATIO NO.STRUCTURE Si Fe Cu Mn Mg Cr Zn Ti Zr Bi OTHERS (%) INVENTION 1 BM 110.20 0.20 — — — — — — — — — 10 EXAMPLE CM 0.20 0.20 — 0.80 0.80 — — — —— — — BM 2 10.20 0.20 — — — — — — — — — 10 2 BM 1 5.00 — — — — — — — —0.10 — 10 CM 0.10 0.10 — 1.00 0.80 — — 0.05 — — — — BM 2 5.00 — — — — —— — — 0.10 — 10 3 BM 1 12.50 — — — — — — — — 0.02 — 10 CM 0.20 0.20 —1.00 0.80 — — — — — — — BM 2 12.50 — — — — — — — — 0.02 — 10 4 BM 110.20 0.20 2.00 — — — 5.00 — — — — 10 CM 0.20 0.20 — 1.00 0.80 — — — — —— — BM 2 10.20 0.20 2.00 — — — 5.00 — — — — 10 5 BM 1 10.20 0.20 — — — —— — — 0.10 — 10 CM 0.20 0.20 0.15 1.20 1.20 — — — — — — — BM 2 10.200.20 — — — — — — — 0.10 — 10 6 BM 1 10.20 0.20 — — — — — — — 0.30 — 10CM 0.20 0.20 — 0.60 1.70 — — — — — — — BM 2 10.20 0.20   — —   — —  0.30 — 10 7 BM 1 10.20 0.20 — — 1.00 — — — — 0.30 In: 0.02 10 CM 0.200.20 1.00 1.00 0.50 — — — — — — — BM 2 10.20 0.20 — — 1.00 — — — — 0.30In: 0.02 10 8 BM 1 10.20 0.20 — — 0.10 — — — — 0.20 Sn: 0.02 10 CM 0.200.70 0.20 1.00 0.50 — — — — — — — BM 2 10.20 0.20 — — 0.10 — — — — 0.20Sn: 0.02 10 9 BM 1 10.20 0.20 — — 1.80 — — — — 0.10 — 10 CM 0.20 0.200.15 1.20 0.80 0.10 — — 0.10 — — — BM 2 10.20 0.20 — — 1.80 — — — — 0.10— 10 10 BM 1 10.20 0.20 — — — — — — — 0.10 Sr: 0.02 10 CM 1.00 0.50 —1.70 0.50 — — — — — — — BM 2 10.20 0.20 — — — — — — — 0.10 Sr: 0.02 1011 BM 1 12.50 — — — — — — — — 0.02 Na: 0.01 10 CM 0.20 0.20 — 1.00 0.80— — — — — — — BM 2 12.50 — — — — — — — — 0.02 Na: 0.01 10 12 BM 1 12.50— — — — — — — — 0.02 — 10 CM 0.20 0.20 — 1.00 0.80 — — — — — — — BM 212.50 — — — — — — — — 0.02 — 10 13 BM 1 10.20 0.20 — — — — — — — 0.10 —10 CM 0.20 0.20 — 1.00 0.80 — — — — — — — BM 2 12.50 — — — — — — — —0.02 — 10 14 BM 12.50 — — — — — — — — 0.02 — 10 CM 0.20 0.20 — 1.00 0.80— — — — — — — 15 BM 12.50 — — — — — — — — 0.02 — 10 CM 0.20 0.20 — 1.000.80 — — — — — — — SAM 0.20 0.20 — — — — — — — — — 10 16 BM 12.50 — — —— — — — — 0.02 — 10 CM 0.20 0.20 — 1.00 0.80 — — — — — — — SAM 0.30 0.30— — — — 2.00 — — — — 10 17 BM 12.50 — — — — — — — — 0.02 — 10 CM 0.200.20 — 1.00 0.80 — — — — — — — SAM 0.30 0.30 — — — — 0.50 — — — In: 0.0210 18 BM 12.50 — — — — — — — — 0.02 — 10 CM 0.20 0.20 — 1.00 0.80 — — —— — — — SAM 0.50 0.50 — — 2.50 — 4.00 — — — Sn: 0.02 10 19 BM 12.50 — —— — — — — — 0.02 — 10 CM 0.20 0.20 — 1.00 0.80 — — — — — — — SAM 0.700.70 0.10 1.50 0.50 1.00 0.10 — — — 10 20 BM 12.50 — — — — — — — — 0.02— 10 CM 0.20 0.20 — 1.00 0.80 — — — — — — — SAM 0.50 1.00 0.50 — — 0.105.00 — — — — 10 21 BM 12.50 — — — — — — — — 0.02 — 10 CM 0.20 0.20 —1.00 0.80 — — — — — — — SAM 1.00 0.30 0.30 — 0.10 — 3.00 — 0.10 — — 10COMPARATIVE R1 BM 1 10.20 0.20 — — — — — — — 0.10 — 10 EXAMPLE CM 0.200.20 — 1.00 0.20 — — — — — — — BM 2 10.20 0.20 — — — — — — — 0.10 — 10R2 BM 1 10.20 0.20 — — — — — — — 0.10 — 10 CM 0.20 0.20 — 1.00 1.20 — —— — — — — BM 2 10.20 0.20 — — — — — — — 0.10 — 10 R3 BM 1 10.20 0.20 — —— — — — — 0.10 — 10 CM 0.20 0.20 — 1.00 1.20 — — — — — — — BM 2 10.200.20 — — — — — — — 0.10 — 10 R4 BM 1 3.00 0.20 — — — — — — — 0.10 — 10CM 0.20 0.20 — 1.00 1.20 — — — — — — — BM 2 3.00 0.20 — — — — — — — 0.10— 10 BM: brazing material CM: core material SAM: sacrificial anodematerial

TABLE 2 INTERMEDIATE ANNEALING ROLLING AND FINAL RATIO FROM ANNEALINGCONDITIONS INTER- TIME FOR TIME FOR BRAZING MEDIATE WHICH WHICH GRAINRESULTS OF ANNEALING STRUCTURE STRUCTURE SIZE MINIATURE TEST THICKNESSIS IS OF CORE TEST FLUID MATE- CLAD TO FINAL MAINTAINED MAINTAINED COOL-CORE MATERIALS COEF- RIAL STRUC- THICKNESS AT 300° C. AT 340° C. INGMATE- NOT FICIENT NO TURE (%) OR MORE (h) OR MORE (b) SPEED RIAL ETCHEDETCHED RATIO α INVENTION 1 BM 1 50 8 3 B A good good A EXAMPLE CM BM 2 2BM 1 50 3.5 1.5 B A good good B CM BM 2 3 BM 1 50 10 6 A A good good ACM BM 2 4 BM 1 50 8 4 A A good good A CM BM 2 5 BM 1 50 8 4 A A goodgood B CM BM 2 6 BM 1 50 8 4 A B good good B CM BM 2 7 BM 1 50 15 8 A Agood good A CM BM 2 8 BM 1 50 8 4 A A good good A CM BM 2 9 BM 1 50 8 4A A good good A CM BM 2 10 BM 1 50 8 4 A B good good B CM BM 2 11 BM 120 8 4 A A good good A CM BM 2 12 BM 1 70 8 4 A B good good B CM BM 2INVENTION 13 BM 1 50 8 4 A A good good A EXAMPLE CM BM 2 14 BM 50 10 6 AA good good A CM 15 BM 50 10 6 A A good good A CM SAM 16 BM 50 10 6 A Agood good A CM SAM 17 BM 50 10 6 A A good good A CM SAM 18 BM 50 10 6 AA good good A CM SAM 19 BM 50 10 6 A A good good A CM SAM 20 BM 50 10 6A A good good A CM SAM 21 BM 50 10 6 A A good good A CM SAM COMPARATIVER1 BM 1 50 10 6 A A fail fail A EXAMPLE CM BM 2 R2 BM 1 90 8 4 A X goodgood X CM BM 2 R3 BM 1 60 2.5 0.5 X X good good X CM BM 2 R4 BM 1 50 8 4A A fail fail B CM BM 2 BM: brazing material CM: core material SAM:sacrificial anode material

As illustrated in Table 1 and Table 2, it has been verified that thetest materials serving as examples of the present invention acquire theexcellent joining state at the acceptable level and the fluidcoefficient ratio α of 0.50 or more.

1-22. (canceled)
 23. An aluminum alloy brazing sheet used for brazing ofan aluminum alloy in an inert gas atmosphere or in vacuum and formed ofa two-layer material in which a brazing material and a core material arestacked in this order, the core material being formed of an aluminumalloy and having a grain size of 20 to 300 μm, the aluminum alloycomprising Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of1.50 mass % or less, and Fe of 1.00 mass % or less, and optionally oneor two or more of Ti less than 0.10 mass %, Cu of 1.20 mass % or less,Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less, with thebalance being aluminum and inevitable impurities, the brazing materialbeing formed of an aluminum alloy comprising Si of 4.00 to 13.00 mass %,and optionally one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless, with the balance being aluminum and inevitable impurities, and ina drop-type fluidity test, a ratio α (α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied being 0.50 or more.
 24. An aluminumalloy brazing sheet used for brazing of an aluminum material in an inertgas atmosphere or in vacuum and formed of a three-layer material inwhich a brazing material, a core material, and a brazing material arestacked in this order, the core material being formed of an aluminumalloy and having a grain size of 20 to 300 μm, the aluminum alloycomprising Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of1.50 mass % or less, and Fe of 1.00 mass % or less, and optionally oneor two or more of Ti less than 0.10 mass %, Cu of 1.20 mass % or less,Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less, with thebalance being aluminum and inevitable impurities, each of the brazingmaterials being formed of an aluminum alloy comprising Si of 4.00 to13.00 mass %, and optionally one or two or more of Bi of 1.00 mass % orless, Na of 0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00mass % or less, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, Inof 0.100 mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass% or less, with the balance being aluminum and inevitable impurities,and in a drop-type fluidity test, a ratio α (α=K_(a)/K_(b)) of a fluidcoefficient K_(a) after a 5% strain is applied to a fluid coefficientK_(b) before the strain is applied being 0.50 or more.
 25. An aluminumalloy brazing sheet used for brazing of an aluminum material in an inertgas atmosphere or in vacuum and formed of a three-layer material inwhich a brazing material, a core material, and a sacrificial anodematerial are stacked in this order, the core material being formed of analuminum alloy and having a grain size of 20 to 300 μm, the aluminumalloy comprising Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %,Si of 1.50 mass % or less, and Fe of 1.00 mass % or less, and optionallyone or two or more of Ti less than 0.10 mass %, Cu of 1.20 mass % orless, Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less, with thebalance being aluminum and inevitable impurities, the brazing materialbeing formed of an aluminum alloy comprising Si of 4.00 to 13.00 mass %,and optionally one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless, with the balance being aluminum and inevitable impurities, thesacrificial anode material being formed of aluminum or an aluminum alloycomprising Zn of 8.00 mass % or less, and optionally one or two or moreof Mn of 2.00 mass % or less, Mg of 3.00 mass % or less, Si of 1.50 mass% or less, Fe of 1.00 mass % or less, Cu of 1.00 mass % or less, Ti of0.30 mass % or less, Zr of 0.30 mass % or less, Cr of 0.30 mass % orless, In of 0.100 mass % or less, and Sn of 0.100 mass % or less, withthe balance being aluminum and inevitable impurities, and in a drop-typefluidity test, a ratio α (α=K_(a)/K_(b)) of a fluid coefficient K_(a)after a 5% strain is applied to a fluid coefficient K_(b) before thestrain is applied being 0.50 or more.
 26. A method for manufacturing thealuminum alloy brazing sheet according to claim 23, the methodcomprising executing at least hot working, cold working, one or moreintermediate annealings between rolling passes in the cold working, andfinal annealing after a last pass of the cold working on a stackedstructure acquired by stacking a brazing material ingot and a corematerial ingot in this order to acquire the aluminum alloy brazingsheet, wherein the core material ingot is formed of an aluminum alloycomprising Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of1.50 mass % or less, and Fe of 1.00 mass % or less, and optionally oneor two or more of Ti less than 0.10 mass %, Cu of 1.20 mass % or less,Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less, with thebalance being aluminum and inevitable impurities, the brazing materialingot is formed of an aluminum alloy comprising Si of 4.00 to 13.00 mass%, and optionally one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless, with the balance being aluminum and inevitable impurities, and aworking ratio (working ratio=((t_(a)−t_(b))/t_(a))×100) of a thicknesst_(b) before the final annealing to a thickness t_(a) after lastintermediate annealing among the intermediate annealings is 20 to 70%.27. A method for manufacturing the aluminum alloy brazing sheetaccording to claim 24, the method comprising executing at least hotworking, cold working, one or more intermediate annealings betweenrolling passes in the cold working, and final annealing after a lastpass of the cold working on a stacked structure acquired by stacking abrazing material ingot, a core material ingot, and a brazing materialingot in this order to acquire the aluminum alloy brazing sheet, whereinthe core material ingot is formed of an aluminum alloy comprising Mn of0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of 1.50 mass % orless, and Fe of 1.00 mass % or less, and optionally one or two or moreof Ti less than 0.10 mass %, Cu of 1.20 mass % or less, Zr of 0.30 mass% or less, and Cr of 0.30 mass % or less, with the balance beingaluminum and inevitable impurities, each of the brazing material ingotsis formed of an aluminum alloy comprising Si of 4.00 to 13.00 mass %,and optionally one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless, with the balance being aluminum and inevitable impurities, and aworking ratio (working ratio=((t_(a)−t_(b))/t_(a))×100) of a thicknesst_(b) before the final annealing to a thickness t_(a) after lastintermediate annealing among the intermediate annealings is 20 to 70%.28. A method for manufacturing the aluminum alloy brazing sheetaccording to claim 25, the method comprising executing at least hotworking, cold working, one or more intermediate annealings betweenrolling passes in the cold working, and final annealing after a lastpass of the cold working on a stacked structure acquired by stacking abrazing material ingot, a core material ingot, and a sacrificial anodematerial ingot in this order to acquire the aluminum alloy brazingsheet, wherein the core material ingot is formed of an aluminum alloycomprising Mn of 0.50 to 2.00 mass %, Mg of 0.40 to 2.00 mass %, Si of1.50 mass % or less, and Fe of 1.00 mass % or less, and optionally oneor two or more of Ti less than 0.10 mass %, Cu of 1.20 mass % or less,Zr of 0.30 mass % or less, and Cr of 0.30 mass % or less, with thebalance being aluminum and inevitable impurities, the brazing materialingot is formed of an aluminum alloy comprising Si of 4.00 to 13.00 mass%, and optionally one or two or more of Bi of 1.00 mass % or less, Na of0.050 mass % or less, Sr of 0.050 mass % or less, Mg of 2.00 mass % orless, Zn of 8.00 mass % or less, Cu of 4.00 mass % or less, In of 0.100mass % or less, Sn of 0.100 mass % or less, and Fe of 1.00 mass % orless, with the balance being aluminum and inevitable impurities, thesacrificial anode material ingot is formed of aluminum or an aluminumalloy comprising Zn of 8.00 mass % or less, and optionally one or two ormore of Mn of 2.00 mass % or less, Mg of 3.00 mass % or less, Si of 1.50mass % or less, Fe of 1.00 mass % or less, Cu of 1.00 mass % or less, Tiof 0.30 mass % or less, Zr of 0.30 mass % or less, Cr of 0.30 mass % orless, In of 0.100 mass % or less, and Sn of 0.100 mass % or less, withthe balance being aluminum and inevitable impurities, and a workingratio (working ratio=((t_(a)−t_(b))/t_(a))×100) of a thickness t_(b)before the final annealing to a thickness t_(a) after last intermediateannealing among the intermediate annealings is 20 to 70%.
 29. The methodfor manufacturing the aluminum alloy brazing sheet according to claim26, wherein a time for which the structure is maintained at 300° C. ormore is three hours or more, a time for which the structure ismaintained at 340° C. or more is one hour or more, and cooling speed is300° C./hour or less in the intermediate annealings.
 30. The method formanufacturing the aluminum alloy brazing sheet according to claim 26,wherein a time for which the structure is maintained at 300° C. or moreis three hours or more, a time for which the structure is maintained at340° C. or more is one hour or more, and cooling speed is 300° C./houror less in the final annealing.
 31. The method for manufacturing thealuminum alloy brazing sheet according to claim 27, wherein a time forwhich the structure is maintained at 300° C. or more is three hours ormore, a time for which the structure is maintained at 340° C. or more isone hour or more, and cooling speed is 300° C./hour or less in theintermediate annealings.
 32. The method for manufacturing the aluminumalloy brazing sheet according to claim 28, wherein a time for which thestructure is maintained at 300° C. or more is three hours or more, atime for which the structure is maintained at 340° C. or more is onehour or more, and cooling speed is 300° C./hour or less in theintermediate annealings.
 33. The method for manufacturing the aluminumalloy brazing sheet according to claim 27, wherein a time for which thestructure is maintained at 300° C. or more is three hours or more, atime for which the structure is maintained at 340° C. or more is onehour or more, and cooling speed is 300° C./hour or less in the finalannealing.
 34. The method for manufacturing the aluminum alloy brazingsheet according to claim 28, wherein a time for which the structure ismaintained at 300° C. or more is three hours or more, a time for whichthe structure is maintained at 340° C. or more is one hour or more, andcooling speed is 300° C./hour or less in the final annealing.
 35. Themethod for manufacturing the aluminum alloy brazing sheet according toclaim 29, wherein a time for which the structure is maintained at 300°C. or more is three hours or more, a time for which the structure ismaintained at 340° C. or more is one hour or more, and cooling speed is300° C./hour or less in the final annealing.
 36. The method formanufacturing the aluminum alloy brazing sheet according to claim 31,wherein a time for which the structure is maintained at 300° C. or moreis three hours or more, a time for which the structure is maintained at340° C. or more is one hour or more, and cooling speed is 300° C./houror less in the final annealing.
 37. The method for manufacturing thealuminum alloy brazing sheet according to claim 32, wherein a time forwhich the structure is maintained at 300° C. or more is three hours ormore, a time for which the structure is maintained at 340° C. or more isone hour or more, and cooling speed is 300° C./hour or less in the finalannealing.